Pyxine janakiae A. Anilkumar & Sequiera, 2025

Pyxine janakiae A. Anilkumar & Sequiera sp. nov. ( Fig. 2 View FIGURE 2 )

Mycobank No.: MB 860432

Similar to P. himalayensis but differs by the absence of pseudocyphellae on thallus, the smaller ascospore size, the brown to brownish orange internal stipe with a white lower part, and lacks zeorin.

Type:— INDIA. Kerala: Idukki district, Mathikettan Shola National Park, Karadippara, 10.007983° N and 77.246951° E, elev. 1780 m, 09 April 2022, Aswathi Anilkumar 5583: ( holotype MCH!, isotype KFRI!).

Thallus saxicolous, foliose, 3–6 cm wide, sub orbicular to orbicular, adnate to tightly adnate. Lobes radiating, sub dichotomous, plane to slightly convex toward the periphery, 1–2.5 mm wide, apices discrete, subrotund to truncate; upper surface shiny, smooth, whitish grey towards distal end, dull, rough, brownish grey towards proximal end, irregularly cracked especially towards older lobes, eciliate, epruinose, emaculate; soredia, isidia, and pseudocyphellae are absent; medulla ochre to orange towards the apices; at some parts, especially towards distal region a yellowish lower medulla is visible in addition to upper orange medulla; lower surface black in the centre, paler towards the margin, with dense, black, simple rhizines.

Apothecia common, cocoes-type, lecideine, ca. 0.5–0.9 mm diam., frequent towards center compared to the margins, laminal, plane to concave. Epihymenium dark brown, 46–50 µm high, K+purple, I+ blue, KI+ blue; hymenium hyaline, 70−112 µm high, K−, I+ blue, KI−; hypothecium light to dark brown, 87–149 µm high; internal stipe brown to brownish orange, inferior part white, K−. Asci 8−spored, 30.5−60.7 × 8.4−12.3 µm; ascospores brown, two-celled, oval to ellipsoid, 11−14 × 5−7 µm. Pycnidia not seen.

Chemistry: UV−, Upper cortex K+ yellow, C−, KC−, P−, Medulla K− or dirty brown, C−, KC−, P−.Atranorin and terpenes detected by TLC.

Additional materials examined ( paratypes): INDIA. Kerala: Idukki district, Mathikettan Shola National Park, Sukumaran Kadu , 9.99438° N and 77.2535° E, elev. 1601 m, on rock, 31 December 2021, Aswathi Anilkumar 5405 (MCH) GoogleMaps ; ibid., Vattapara , 10.004425° N and 77.239209° E, elev. 1680 m, on rock, 12 April 2022, Aswathi Anilkumar 5818 (MCH) GoogleMaps .

Etymology: Pyxine janakiae is named in honour of Dr. E.K. Janaki Ammal, for her outstanding contributions to Botany.

Distribution and ecology: On rocks in montane wet grasslands (elevation of 1460–1780 m) of Mathikettan Shola National Park, Idukki, Kerala, India. Found associated with other lichen species such as Buellia quartziana S.R. Singh & D.D. Awasthi (1981: 189) , Pertusaria indica Preeti Srivast. & D.D. Awasthi (1993: 212) , Parmotrema grayanum (Hue) Hale (1974: 336) and Lecanora oreinoides (Körb.) Hertel & Rambold (1989: 100) . The species is currently known from Mathikettan Shola National Park only.

Notes: Pyxine janakiae is characterised by its ochre to orange medulla, the absence of vegetative propagules, cocoes-type apothecia and an internal stipe which is brown to brownish orange with a white colouration in lower region. P. janakiae has resemblance with Pyxine himalayensis D. D. Awasthi (1980: 371) , Pyxine schechingeri Kalb (1987: 71) , Pyxine pungens Zahlbruckner (1928:210) , Pyxine rhodesiaca Vainio ex Lynge (1937: 90) and Pyxine elixii Kalb (1994: 64) .

P. himalayensis have similarity with P. janakiae in having an orange medulla, cocoes-type apothecia and both lack vegetative propagules as well. However, in P. himalayensis , thallus is clearly maculate which later converts into distinct pseudocyphallae. The species is known to have zeorin as a lichen substance (in some populations or trace amounts), larger ascospore size, and a hyaline internal stipe ( Awasthi 1982, Yang et al. 2018). In contrast, P. janakiae lacks maculae or pseudocyphallae, smaller ascospore size and the internal stipe is brown to brownish orange with a white lower part. Both the species have similarity in microchemical colour tests, but in P. janakiae a dirty brown colour is formed on the application of K on medulla.

Pyxine schechingeri is having resemblance with P. janakiae in having saxicolous, orbicular, brownish grey thallus and having smooth, shiny, convex to plane, emaculate lobes, completely ochre to orange medulla and both lacks vegetative propagules. But Pyxine schechingeri has an obscurascence-type apothecium, the internal stipe is reddishbrown with a white lower part and has norstictic acid as a lichen substance ( Kalb 1987, Jungbluth 2011). Whereas, P. janakiae has cocoes-type apothecia, internal stipe with brown to brownish orange with a white lower part, and also lacks norstictic acid. Both have variations in the micro-chemical colour test.

Pyxine pungens View in CoL share significant similarities with P. janakiae in upper cortex morphology, cocoes type-apothecia, absence of vegetative propagules, and secondary chemistry. However, in P. pungens View in CoL , the medulla is not entirely orange as in P. janakiae ; the medulla has upper orange region and a lower white region. Additionally, the internal stipe of P. pungens View in CoL is orange, K+ whereas in P. janakiae , the internal stipe is brown to brownish orange, with the distinctly visible white lower part, K− ( Jungbluth 2011, Rogers 1986, Zahlbruckner 1928). Furthermore, both species have entirely different micro-chemical colour tests.

P. rhodesiaca have ochre to orange coloured medulla, secondary chemistry and both lack vegetative propagules. Eventhough, medulla is ochre to orange but the lower medulla is not orange but white. And, P. rhodesiaca is strictly maculate with laminal as well as marginal pseudocyphellae, larger ascospore size, and the internal stipe is white (rarely, the upper part exhibits the colour of medulla). The micro-chemical colour tests are also different ( Jungbluth 2011).

P. elixii also shows similarity with P. janakiae in having orange medulla, secondary chemistry and both lack vegetative propagules. But, P. elixii has a maculate thallus, white to dirty brown internal stipe, and obscurascence-type apothecia ( Kalb, 1994).

Pyxine endocrocea Kalb (1987:80) and Pyxine cognata Stirton (1879:311) View in CoL have similarities in the colour of the medulla and both lack vegetative propagules like P. janakiae , but were excluded because both were UV+ with the presence of lichexanthone ( Aptroot 2014).

Key to the Indian species of yellow-orange medullated Pyxine View in CoL

1a. Thallus UV +, lichexanthone present ..................................................................................................................................................2

1b. Thallus UV –, lichexanthone absent....................................................................................................................................................5

2a. Thallus with vegetative propagules ....................................................................................................................................................3

2b. Thallus without vegetative propagules...............................................................................................................................................4

3a. Thallus isidiate...................................................................................................................... P. punensis Nayaka & Upreti (2013 View in CoL :04)

3b. Thallus sorediate............................................................................................................................... P. subcinerea Stirton (1898:397) View in CoL

4a. Thallus saxicolous, internal stipe pale brown, K + purple .................................................... P. nilgiriensis D.D. Awasthi (1982:374)

4b. Thallus corticolous, internal stipe colourless to brown, K-....................................................... P. berteriana (Fée) Imsh. (1957:254) View in CoL

5a. Thallus with vegetative propagules ....................................................................................................................................................6

5b. Thallus without vegetative propagules.............................................................................................................................................13

6a. Thallus isidiate....................................................................................................................................................................................7

6b. Thallus sorediate...............................................................................................................................................................................11

7a. Isidia squamiform.............................................................................................................................. P. endochrysina Nyl. (1890:34) View in CoL

7b. Isidia cylindrical or granular, globose to filiform...............................................................................................................................8

8a. Medulla K–, P+ orange; isidia cylindrical to clavate ....................................................................... P. coralligera Malme. (1897:40)

8b. Medulla K-, P- ....................................................................................................................................................................................9

9a. Thallus saxicolous, pseudocyphellae indistinct...................................................................... P. palniensis D.D. Awasthi (1982:374)

9b. Thallus corticolous, pseudocyphellae distinct..................................................................................................................................10

10a. Isidia nodular-clavate, apically brown–black..................................................................... P. austroindica D.D. Awasthi (1982:364)

10b. Isidia filiform........................................................................................................................... P. keralensis D.D Awasthi (1982:372) View in CoL

11a. Soralia farinose, laminal....................................................................................................................... P. farinosa Kashiw. (1977:67) View in CoL

11b. Soralia coarse, marginal to submarginal...........................................................................................................................................12

12a. Medulla K+ red, soralia grey.................................................................................................... P. sorediata (Ach.) Mont. (1842:188) View in CoL 12b. Medulla K-, soralia yellow ................................................................................................................. P. meissnerina Nyl. (1873:164) View in CoL

13a. Thallus with yellow to deep yellow medulla.................................................................. P. yercaudensis Nayaka & Upreti (2013 View in CoL :06)

13b. Thallus with orange medulla ............................................................................................................................................................14

14a. Internal stipe hyaline; maculate lobes with distinct pseudocyphellae, zeorin present ......................... P. himalayensis D.D. Awasthi

14b. Internal stipe brown to brownish orange with a white colouration in lower region; pseudocyphellae absent, emaculate, epruinose, lobes............................................................................................................................. P. janakiae A. Anilkumar & Sequiera sp. nov.